Here for someone

Understanding services · England & Wales

What “they have capacity” means

Services may say an adult can decide for themselves, even when the decision seems dangerous or difficult to understand.

Short answerCapacity is not a blanket judgement about a person. It is about whether they can make one particular decision at the time it needs to be made. Mental illness, unusual behaviour or an unwise choice does not by itself prove that someone lacks capacity.
If there is danger to life, call 999. For urgent mental-health help, call NHS 111 and select the mental-health option. Do not wait for a capacity dispute to be resolved first.

Five things families need to know

  1. Capacity is decision-specific. Someone may be able to decide what to eat but not be able to make a more complex decision about treatment or money.
  2. It is time-specific. Capacity can change. A person may be able to make the same decision at a different time.
  3. The starting point is that the person has capacity. They must also be given practical help to understand and make the decision before they are treated as unable to do so.
  4. An unwise decision is not enough. The law does not allow capacity to be rejected only because other people disagree with the choice.
  5. A proper assessment is needed where capacity is in doubt. It looks at whether an impairment or disturbance of the mind or brain means the person cannot understand, retain, use or weigh the relevant information, or communicate the decision.
Sources: GOV.UK and NHS
Government guidance on the Mental Capacity Act and the NHS Mental Capacity Act guide.

What you can ask

Clarify the assessment“Which specific decision was their capacity assessed for, and when was it assessed?”
Ask how they were supported“What information were they given, and what support was used to help them understand, weigh and communicate the decision?”
When capacity may fluctuate“Their presentation changes during the day. Please record what I have observed and consider whether the decision needs to be assessed again when their condition changes.”
Who assesses capacity?

The person responsible for the decision will usually assess capacity. For a treatment decision, that may be the clinician proposing the treatment. More serious or disputed decisions may need a more formal assessment. Ask who made the assessment and whether it is recorded.

What happens if they lack capacity?

A decision made for someone who lacks capacity must be in their best interests and use the least restrictive option. Government guidance says family, friends and carers should normally be consulted where practical and appropriate. This does not mean the family automatically makes the decision.

Mental Capacity Act and Mental Health Act are different

The Mental Capacity Act covers decisions made for someone who cannot make a particular decision. The Mental Health Act has separate powers concerning assessment, detention and treatment for mental disorder. Someone can have capacity for a decision and still be assessed under the Mental Health Act. Being detained under the Mental Health Act also does not automatically mean they lack capacity for every decision.

Rethink Mental Illness explains the difference.

If you disagree with the assessment

Ask for the concern to be recorded and for an explanation of the decision and evidence used. Ask whether it should be reviewed because the decision, timing or person's condition has changed. For an unresolved concern about NHS care, the services-say-no guide explains PALS and complaints.

Related guides

They will not accept helpWhen services say noIf they are sectioned

Here for Someone is an independent information project, not a legal service. This page summarises the Mental Capacity Act 2005 for England and Wales using the linked public guidance. Scotland and Northern Ireland have different laws.

Sources checked: 27 August 2026

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